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M. 'J. A. CULMORE.

DRILL BIT.

APPLICATION FILED JULY 30.1918.

1 ,306371 Patented June 10, 1919 2 SHEETSSHEET I.

- wywaam ATTORNEYS .J. A. CULMORE.

DRILL BIT.

APPLICATION FILED JULY 30, I918- Patented June 10, 1919.

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p ifi n f L er P ent. rammed June to, rate.

Applimtion filed July so, 1918. Serial No. 247,450. a

To all whom it may concern:

Be it known that 1, MARCH J. A. CULMORE, a citizen of the United States,residing at Houston, in the county of Harris and State of Texas, haveinvented certain new and use ful Improvements in Drill-Bits, of whichthe following is a specification.

This invention relates to new and useful improvements in a drill bit.

The object of the invention is to provide a bit of the characterdescribed, which has been especially designed for the purpose ofdrillingthrough rock, or other hard formations and is also adapted foruse in drilling through softer formations. such as shale.

Another object of the invention is to provide a bit of the characterdescribed, having rotatable cutters formed in sections, said sectionsbeing reversible so as to adapt the 'bit for drilling, either throughrock and hard formations or for drilling through shale, and similarformations. Another feature of the invention resides in the provision ofside reamers which are provided for the purpose of reaming out and thebore formed by the bit.

1 or feature of the invention resides in the provision of a novel meansfor lubricating the bearings. v Wifi the above and other objects inview, the invention has particular relation to certain novel featuresofconstruction, operation and arrangement of parts. an example of whichis given in this specification and illustrated in'the accompanyingdrawings, wherein:

1 1, is a side view of the bit. Fig. 2, is a top plan view. Fig. 3, is aside view of the form of bi especially adapted for drilling throughrock, and shown partially in section, and

Fig. 4, is a side view of a modified form which is especlally adaptedfor drilling through shale and shown partially in sec- 1 1 now moreparticularly to the wherein like numerals of reference-d ate similarparts in each of the e numeral 1, designates the h ad,

which is preferably formed of one piece. and whose shank 1' isexternally threaded to fit a standard .pipe coupling, and whose lowerend has a transverse ll-shaped recess. form ing the faces 2. 2.extending at approximately a 90 degree angle to each other. and drilledthrough the head on each side at approximately right angles to the faces2, 2. are the holes 3, 3. which are provided to receive bearing spindles4. 4. The outer ends of the holes 3, 3. are enlarged, forming therecesses 5, 5, and the bearing surfaces 6. 6. forming end bearings forthe side reamers 7. 7. The bearing surfaces 6, 6. are counter-bored, asat 7, to receive the annularbosses 8 of the spindles 4. The outer end ofeach reamer 7 is counter-bored. at 9. to receive the nuts 10. 10, whichare threaded on the outer end of the spindle 4. and seated in saidcounterthe corresponding face 2. and interposed between said section andits face is a hardened washer 14, which rests in a counter-bore in thehead. The inner face of this section is oounterbored. to receive thehardened washer 15. against which the second section 12. fits. theadjacent end of the last mentioned section being counter-bored toreceive the hardened washer 16. and these sections Hand 12 have bushings17 and 18. preferably of brass or other similar'material which formbearings on the spindles 4. These sections 11 and 12 are milled withteeth. as shown in Figs. 3 and 4. said sections and teeth being beveledeach way from a circumferential line. so that they will be reversible.The point of each cutter is formed of the conical shaped section-13.which has a smooth counter-bore 19. to receive the nut 20, which is th dupon the inner end of the cone sponding spindle 4, and a retaining ring21, is screwed into a corresponding internally threaded counter-bore inthe face of said section to retain the same upon the end of the spindle4. This ring 21 is hardened and operates against the hardened washer 22,which is counter-sunk into the adjacent face of the section 12.

Dowel pins are used to hold the washers, between the sections, in place,and to hold the boss 8 of each spindle 4 in position in the head. Theshank of the head has the internally threaded socket 23, to receive theexternally threaded lower end of a lubricant retainer 24, and leadingfrom this retainer are the conduits, 25, 25 which terminate in thespindle bearings. The spindles have the respective ducts 26 boredtherethrough, from the inner end to near the outer end thereof andradiatin from each duct 26 are the outlets 27, throug 1 which thelubricant is conducted to the reamer bearing, and to the bearings of theroller sections, one of said outlets being arranged opposite the dis-.charge end of the conduit 25, through which lubricant is introduced intothe duct 26, of the corresponding spindle. All of the bearings are thuscontinuously lubricated.

Water passageways 28, 28, are bored down through the head outside of thelubricant retainer 24, and terminate in the angle formed between thefaces 2, 2. The bit is attached to the lower end of the drill stem inthe well known manner, and water is forced down through said stem andthrough the water passageways 28, 28, and reaches the cutters to carryaway the cuttings therefrom.

In drilling through hard rock, the sections of the'cutting rollers arearranged, as shown in Fig. 3, so as to give said rollers substantially aconical shaped form, the sections fitting up closely together. Whenshale or other comparatively soft formation 15 encountered, the sections11 and 12, may be reversed, and they are so beveled that when reversed,their operative faces will be spaced apart, as shown in Fig. 4:, thusforming operative faces on the rollers that will penetrate anddisintegrat ashale-like formatlon very rapidly.

I It 1s obvious that the roller sections can be milled or toothed in anydesired manner, soas to present an abrading or cutting operativesurface, depending upon the character of the formation to be pierced,and it is further obvlousthat the sections of one roller I may bearranged in staggered relation with respect to the sections of the otherroller, so

that the rolleron one side of the head will cut away any formation whichmay be left by the roller on the other side.

What I claim is: 1. A drill including a head, whose lower proximatelyright angles to the respective faces, an approximately conical shapedcutting roller rotatably mounted on the inner end of each spindle, andformed of independent sections, and a reaming roller rotatably mountedon the outer end of each spindle.

3. A drill including a head, provided with a lubricant conduit, aspindle carried by the head, a cutting roller mounted on the spindle,and being approximately conical shaped in contour, said roller beingcomposed of independent sections, aduct in said spindle communicatingwith the conduit and terminating in the roller bearings, a lubricantretainer from which lubricant is discharged through said conduit andduct to the roller bearing, and a side reamer mounted on the outer endof the s indle.

4:. A drill inclu ing a head, whose lower end is formed with divergingfaces, spindles anchored in the head, and extending at approximatelyright angles to the respective faces, said head being formed with arecess on each side, into which the outer end of the corresponding indleprojects, an approximately conical s aped cuttin roller rotatablymounted on the inner end of each spindle, and formed of independentsections, and a reamer located in each recess of the head, and rotatablymounted upon the outer ends of the spindles.

5. A drill including a head, having a face angularly disposed relativeto the axis of the head, a spindle anchored in the head, atapproximately right angles to said face, whose.inner end projects beyondsaid face, and whose outer end extends beyond said head,an-approximately conical shaped cuttin roller rotatably mounted on thespindle an operatin against said face, said roller being forme ofindependent sections, a reamer rotatably mounted upon the outer end ofthe spindle, said spindle being provided with a lubricant duct, whichterminates in the roller and the reamer bearings, a lubricant retainerand a conduit leading there- (flrom and communicating with the spindleanchored in the head and extending at 'right' angles to the respectivefaces, an approximately conical shaped cutting roller rotatably mountedon the inner end of each spindle and a reamer carried by the outer endof each spindle.

7. A drill including a head, Whose lower end is formed with dlvergingfaces, spindles anchored in the head, and extending at approximatelyright angles .to the respective 10 faces, a cutting roller mounted onthe inner CH J. A. CULMORE.

Witnesses:

E. V. HARDWAY, IRENE BRUNS.

